An automatic tourniquet dynamic control method and system

Abstract

This invention belongs to the field of automation control and dynamic monitoring technology. It proposes a dynamic control method and system for an automatic tourniquet. Specifically, after the automatic tourniquet is activated, during the repressurization process where the airbag pressure recovers from the low-pressure release range to the high-pressure maintenance range, the airbag pressure value and airbag pressure change rate are acquired in real time. The repressurization deviation state is calculated based on the airbag pressure value and airbag pressure change rate. Finally, the output state of the inflation device or the depressurization state of the depressurization device is dynamically adjusted according to the repressurization deviation state. This effectively quantifies the risk of repressurization lag or sudden overshoot caused by multiple cycles during the current repressurization process, providing state variables for identifying the timing deviation and stability decrease of the high-pressure hemostasis platform in multiple inflation and deflation cycles. This allows the tourniquet to maintain a more reliable hemostatic pressure platform during multiple depressurization and repressurization cycles, reducing the risk of continuous bleeding, rebleeding, and frequent pressure fluctuations.

Description

Technical Field

[0001] This invention belongs to the field of automation control and dynamic monitoring technology, specifically relating to an automatic tourniquet dynamic control method and system. Background Technology

[0002] Automatic tourniquets are used in cases of severe bleeding from limb trauma, but they cannot rely solely on sufficiently high pressure to achieve continuous and reliable hemostasis. Existing hemostasis standards clearly require that bleeding be verified after tourniquet application to ensure it is truly under control, with the disappearance of distal pulses as a key criterion. If distal pulses are still present, the tourniquet should be tightened further or additional pressure applied. Existing technologies, such as an automatically adjustable tourniquet in publication CN109009314A, only involve automatically pressurizing, tightening, or maintaining pressure based on the current pressure or tightness. However, they neglect the pressure transition control process when the automatic tourniquet switches from a low-pressure release state to a high-pressure holding state in intermittent pressure release mode. In particular, they fail to consider the contradiction that excessively fast repressurization speed can lead to pressure overshoot, while excessively slow repressurization speed can prolong low-pressure exposure time, resulting in the risk of repressurization deviation. The core issue is the difficulty in controlling the repressurization rate after the low-pressure release of an automatic tourniquet: repressurization too quickly can lead to pressure overshoot, while repressurization too slowly prolongs the low-pressure exposure time. This is because after the low-pressure release window ends, the automatic tourniquet needs to restore the cuff pressure to the high-pressure maintenance range. If the inflation device output is directly increased to shorten the repressurization time, pressure overshoot can easily occur when the cuff pressure approaches the high-pressure target. If a conservative pressurization strategy is adopted to avoid overshoot, the cuff pressure will remain between the low-pressure and high-pressure ranges for an extended period, causing repressurization lag. The former can cause the cuff pressure to briefly exceed the high-pressure maintenance range, resulting in overpressure on the tourniquet, triggering protective decompression, or causing subsequent pressure fluctuations, thus disrupting the stability of the high-pressure hemostasis. The latter can passively prolong the low-pressure release window, leaving the wound site in a state of insufficient compression during the period when high-pressure blockage should be restored, increasing the risk of continued bleeding or rebleeding. More importantly, in actual operation, automatic tourniquets need to repeatedly perform high-pressure maintenance, low-pressure release, and repressurization. The airbag material will exhibit differences in elastic rebound and residual deformation after repeated inflation and deflation; the pressure relief device will show differences in closing response after multiple opening and closing cycles; the release state of residual pressure in the tubing will also change with each cycle; and the inflation device's pressure-boosting capacity will drift due to temperature rise and battery voltage drop. The same inflation output may correspond to different pressure rise rates, repressurization arrival times, and residual pressure after pump shutdown in different cycles, making repressurization abnormalities cyclically cumulative. If fixed pressure feedback parameters are still used for control, the risk of repressurization deviation increases sharply. Repressurization may be normal in previous cycles but lagging in subsequent cycles. Even after a low-pressure release in a certain cycle, the airbag rebound and residual pressure in the tubing can cause a sudden overshoot, leading to catastrophic errors in the timing and stability of the high-pressure tourniquet's reconstruction across multiple cycles. Existing pressure feedback control typically only inflates or stops inflation based on the current pressure deviation, lacking segmented control over the pressure response differences at the initial, middle, and final stages of repressurization. This makes it difficult to simultaneously achieve rapid repressurization and prevent overrush. Therefore, there is an urgent need for a dynamic control method and system for automatic tourniquets. Summary of the Invention

[0003] The purpose of this invention is to propose an automatic tourniquet dynamic control method and system to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0004] To achieve the above objectives, according to one aspect of the present invention, an automatic tourniquet dynamic control method is provided, the method comprising the following steps:

[0005] S100, activate the automatic tourniquet, control the airbag pressure to enter the preset high pressure holding range, so that the automatic tourniquet is in a high pressure holding state; S200, when the pressure relief condition is reached, the pressure of the airbag is controlled to drop from the high pressure holding range to the preset low pressure release range, so that the automatic tourniquet is in the low pressure release state. S300, when the low-pressure release state ends, control the airbag pressure to return from the low-pressure release range to the high-pressure holding range, and return to step S200 after the airbag pressure enters the high-pressure holding range. Step S300, in the process of restoring the airbag pressure from the low-pressure release range to the high-pressure holding range, includes: S301, real-time acquisition of airbag pressure value and airbag pressure change rate; S302, calculate the re-pressure deviation state based on the airbag pressure value and the airbag pressure change rate; S303, dynamically adjusts the output state of the inflation device or the pressure relief state of the pressure relief component according to the pressure deviation state.

[0006] Further, in step S100, the method for controlling the airbag pressure to enter the preset high-pressure holding range so that the automatic tourniquet is in a high-pressure holding state is as follows: the real-time pressure value of the airbag is obtained, and the inflation device is controlled to inflate the airbag according to the relationship between the real-time pressure value of the airbag and the preset high-pressure holding range; when the real-time pressure value of the airbag enters the preset high-pressure holding range, the real-time pressure value of the airbag is monitored, and if the real-time pressure value of the airbag is maintained within the preset high-pressure holding range within a preset confirmation time, it is determined that the automatic tourniquet is in a high-pressure holding state.

[0007] The goal of this step is to prevent the airbag pressure from being mistakenly identified as being in a high-pressure holding state only for a short period of time, thereby improving the reliability of the initial state of the automatic tourniquet's subsequent decompression and recompression cycle control.

[0008] Further, in step S200, when the pressure relief condition is met, the method for controlling the airbag pressure to decrease from the high pressure holding range to the preset low pressure release range, so that the automatic tourniquet is in a low pressure release state, is as follows: when the preset pressure relief condition is met, the pressure relief component is opened to reduce the airbag pressure; after the real-time pressure value of the airbag enters the preset low pressure release range, the pressure relief component is closed or the pressure relief intensity is reduced, and when the real-time pressure value of the airbag remains within the preset low pressure release range within the preset release confirmation time, the low pressure release state is determined.

[0009] The pressure relief conditions may include the high pressure holding time reaching a preset holding time, receiving a pressure relief control command, or meeting other preset cyclic control conditions.

[0010] The goal of this step is to prevent the airbag pressure from briefly entering the low-pressure release range and then continuing to penetrate downwards, thus ensuring a relatively stable initial pressure state during the subsequent repressurization process.

[0011] Further, in step S300, when the low-pressure release state ends, the method for controlling the airbag pressure to return from the low-pressure release range to the high-pressure holding range, and returning to step S200 after the airbag pressure enters the high-pressure holding range, is as follows: when the preset re-pressure condition is met, the inflation device is controlled to inflate the airbag, causing the airbag pressure to rise from the preset low-pressure release range; after the real-time airbag pressure value enters the preset high-pressure holding range, the output of the inflation device is stopped or reduced, and when the real-time airbag pressure value remains within the preset high-pressure holding range within the preset re-pressure confirmation time, it is determined that the automatic tourniquet is back in the high-pressure holding state, and the process returns to step S200.

[0012] Step S300 is used to restore the airbag pressure to a preset high-pressure holding range after the low-pressure release state ends, and to re-enter the high-pressure holding state of the automatic tourniquet. The preset re-pressure conditions may include the low-pressure release time reaching a preset release time, receiving a re-pressure control command, or meeting other preset cycle control conditions.

[0013] Furthermore, after the real-time pressure value of the airbag enters the preset high-pressure holding range, the controller continues to monitor the real-time pressure value of the airbag within a preset re-pressure confirmation time. If the real-time pressure value of the airbag remains within the preset high-pressure holding range within the preset re-pressure confirmation time, it is determined that the automatic tourniquet has re-entered the high-pressure holding state from the low-pressure release state, and the process returns to step S200 to continue determining the next round of pressure release conditions. The goal of this step is to enable the automatic tourniquet to form a cyclical control process of high-pressure holding, low-pressure release, and re-pressure return.

[0014] Furthermore, in step S301, the method for acquiring the airbag pressure value and airbag pressure change rate in real time is as follows: when the low-pressure release state ends and the repressurization process begins, the airbag pressure value is continuously collected according to the preset sampling period. The preset sampling period ranges from 10 to 50 times per second, with a default value of 20 times per second. The moment when the airbag pressure value data is obtained is recorded as the sampling moment. The preset sampling period can be set according to the pressure sensor response speed, controller processing power, and inflation device pressurization speed. For example, it can be set to a fixed period in the range of several milliseconds to several hundred milliseconds, as long as it can meet the pressure change tracking requirements during the repressurization process.

[0015] After obtaining the airbag pressure value at each sampling time, the airbag pressure change rate is calculated based on the ratio of the pressure difference between the airbag and the previous sampling time to the fixed period length.

[0016] The airbag pressure change rate is the difference between the airbag pressure value at the current sampling time and the airbag pressure value at the previous sampling time, divided by the time interval between adjacent sampling times, to obtain the real-time rise rate of the airbag pressure during the repressurization process. When the airbag pressure change rate is large, it indicates that the current repressurization speed is fast, and the tendency of repressurization overshoot should be monitored in subsequent control. When the airbag pressure change rate is small, it indicates that the current repressurization speed is slow, and the tendency of repressurization lag should be monitored in subsequent control.

[0017] Further, in step S302, the method for calculating the re-pressure deviation state based on the airbag pressure value and the airbag pressure change rate is as follows: obtain the airbag pressure value in the high pressure maintenance state before the current depressurization to form a high pressure sequence, and define the lower quartile value of the high pressure sequence as the lower limit of the high pressure reference. The airbag pressure value measured at the end of the low-pressure release state is defined as the low-pressure reference pressure, and the difference between the lower limit of the high-pressure reference and the low-pressure reference pressure is the pressure application interval; then the difference between the airbag pressure value and the low-pressure reference pressure at any sampling time is recorded as the pressure application degree, and the ratio of the pressure application degree to the pressure application interval is recorded as the repressurization ratio. The difference between the re-voltage ratio at any sampling time and the previous sampling time is denoted as the re-voltage residual. If the rate of change of airbag pressure is less than the preset pressure increase threshold, it is determined that a pressure lag has occurred; otherwise, it is determined that a pressure overshoot has occurred. A time domain is preset as the hostage interval, with a value range of 0.5-2 seconds; If the airbag pressure change rate at a sampling time is at a maximum value and pressure overshoot occurs, it is marked as an overshoot point. If the airbag pressure change rate at a sampling time is at a minimum value and pressure lag occurs, it is marked as a lag point. The proportion of sampling times in the holding interval where pressure overshoot occurs corresponding to the overshoot point is defined as the overshoot rate. The product of the maximum value of the re-pressure residual at the sampling time where pressure overshoot occurs and the overshoot rate is the overshoot fraction. The proportion of sampling times in the strangulation interval where pressure lag occurs corresponding to the lag point is defined as the lag rate. The product of the absolute value of the minimum value of the repressurization residual in the sampling time where pressure lag occurs and the lag rate is the lag fraction. During the re-pressure process, the re-pressure deviation is calculated each time a lag point or overshoot point is detected. The calculation method is the ratio of the weighted average of all overshoot fractions to the time-weighted average of all lag fractions. The corresponding weight of the time-weighted average is the time-weight value, which defaults to exp(-ti), where exp is an exponential function with the natural constant e as the base, and ti is the number of sampling times between the lag point or overshoot point and the current sampling time. The larger the value, the farther away it is from the current sampling time.

[0018] The repressurization deviation based on overshoot and hysteresis points essentially uses the pressure change pattern during the repressurization process of the airbag to infer whether the current pneumatic system has deviated from the normal repressurization trajectory. After multiple rounds of operation of the automatic tourniquet, the airbag material will experience differences in elastic rebound and residual deformation due to repeated inflation and deflation, causing changes in the pressurization rate corresponding to the same inflation output. Similarly, the pressure relief device will exhibit differences in closing response after multiple opening and closing, resulting in inconsistent residual relief states at the end of low-pressure release. Therefore, repressurization anomalies will not only manifest as whether the pressure reaches the target, but will first appear as a localized sudden increase or lag in the rate of pressure change. By using overshoot, hysteresis points, and their time-weighted average to form the repressurization deviation state, this dynamic imbalance caused by material rebound, valve hysteresis, and residual pressure in the air path can be quantitatively analyzed, thus providing a basis for subsequent adjustment of the inflation output.

[0019] Since the repressure deviation state is obtained through dynamic analysis of the airbag pressure value and airbag pressure change rate, it can effectively quantify the risk of repressure deviation in the current repressure process, where the previous rounds of repressure were normal but subsequent rounds were lagging. It provides a variable to identify sudden overshoot that could lead to catastrophic errors in the timing and stability of the high-pressure hemostasis platform during multiple cycles. However, the time-weighted construction of the repressure deviation state is dependent on the overshoot point and subsequent points, leading to update lag issues for a large number of data points during continuous judgment. This is especially problematic when continuously acquiring low-volatility data, which can result in missing source data, causing lag and loss of sensitivity for subsequent judgments. Existing technologies cannot solve this update lag problem. To better address this issue and eliminate the update lag, this invention proposes a more preferred solution as follows: Preferably, the method of calculating the re-pressure deviation state every time a lag point or overshoot point is found is replaced by: calculating the re-pressure deviation state once at each sampling moment during the re-pressure process; Within the current holding interval, the proportion of sampling times where pressure boosting overshoot occurs is recorded as the current overshoot rate. The maximum value of the complex pressure residual within the current holding interval is extracted as the positive extreme value of the complex pressure residual. The current overshoot rate and the current positive extreme value of the complex pressure residual are combined into a pair, which is recorded as the overshoot pair. Here, the current holding interval refers to the holding interval corresponding to the current sampling time. The percentage of sampling times with pressurization lag within the current holding interval is used as the current lag rate. The remaining pressurization ratio is calculated from the pressurization ratio. The current lag rate and the remaining pressurization ratio are combined to form the lag tuple corresponding to the current sampling time. The remaining repressurization ratio here is the difference between 1 and the repressurization ratio; The overshoot pairs corresponding to the overshoot points marked in the current re-pressing process and the previous at least one re-pressing process are used to form an overshoot pair set, and the lag pairs corresponding to the lag points marked in the current re-pressing process and the previous at least one re-pressing process are used to form a lag pair set. The overshoot fitting operator is obtained based on the normalized distance between the current overshoot binary and the set of overshoot binary; the lag fitting operator is obtained based on the normalized distance between the current lag binary and the set of lag binary; the complex pressure deviation state is calculated based on the overshoot fitting operator and the lag fitting operator.

[0020] The calculation process of the overshoot fitting operator is as follows: First, normalize the two features in the overshoot binary pair respectively, and take the Euclidean distance between the current overshoot binary pair and any element in the overshoot binary pair set as the overshoot distance dj, and take the average value of each exp(-dj) as the overshoot fitting operator. The calculation process of the lag fitting operator is as follows: First, normalize the two features in the lag pair respectively, and take the Euclidean distance between the current lag pair and any element in the lag pair set as the lag sub-distance di, and take the average value of each exp(-di) as the lag fitting operator.

[0021] Specifically, the complex pressure deviation state R is calculated based on the overshoot fitting operator and the hysteresis fitting operator. k The process is as follows: the current sampling time is recorded as the k-th sampling time, and all sampling times within the current holding interval are used to form a sampling time set Ωk; for any sampling time i in Ωk, the interval between the number of sampling times between the i-th sampling time and the current sampling time is recorded as t. i , where t i =ki; denote the overshoot fitting operator corresponding to the i-th sampling time as O. i Let L be the hysteresis fitting operator corresponding to the i-th sampling time. i According to formula R k =[Σ i∈Ωk exp(-t i )·O i ] / [Σi∈Ωk exp(-t i )·L i +ε], where exp() is an exponential function with the natural constant e as the base, ε is a minimal positive number to prevent the denominator from being zero, and R k A larger value indicates a greater tendency for overshoot in the current complex pressure state, while a smaller value indicates a greater tendency for lag. In the formula, the numerator represents the cumulative overshoot fitting degree of all sampling times within the current clamping interval after time-weighted adjustment, and the denominator is the cumulative lag fitting degree of all sampling times after time-weighted adjustment. The exponential function is used to interpret data timeliness and avoid the influence of early overshoot or lag on aging. Preferably, exp(-ti) is expressed as exp( t i / λ) is replaced by λ, which is the time-related attenuation coefficient used to adapt to different sampling frequencies.

[0022] Further, in step S303, the method for dynamically adjusting the output state of the inflation device or the depressurization state of the depressurization component according to the repressurization deviation state is as follows: the change rate of the airbag pressure calculated in the current repressurization stage and at least one previous repressurization stage is used to form a change rate set; the elements in the change rate set whose values ​​are within the preset repressurization speed range are recorded as the standard change rate, and the repressurization deviation state corresponding to each standard change rate constitutes a repressurization deviation balance sample set. The deviation range of complex pressure from equilibrium is determined based on the complex pressure deviation from equilibrium sample set, wherein the lower quartile value of the complex pressure deviation from equilibrium sample set is used as the lower limit of equilibrium, and the upper quartile value of the complex pressure deviation from equilibrium sample set is used as the upper limit of equilibrium. When the current repressurization deviation is below the lower limit of the repressurization deviation equilibrium range, it is determined that the current repressurization process is mainly characterized by repressurization lag, and the output intensity of the inflation device is increased by 1%-20%. When the current repressurization deviation is higher than the upper limit of the repressurization deviation balance range, it is determined that the current repressurization process is mainly due to repressurization overshoot, and the output intensity of the inflation device is reduced by 1%-20%; or the pressure relief component is controlled to perform pressure relief correction after the airbag pressure value reaches the lower limit of the high pressure reference.

[0023] To ensure the continuity of control in step S303, when no new repressurization deviation state is generated at the current sampling time, the controller can use the most recently calculated repressurization deviation state to adjust the output of the inflation device. Since the repressurization deviation state is constructed using time-dependent weights, the influence of historical points further from the current time is weaker; therefore, using the most recently calculated repressurization deviation state will not dominate subsequent control indefinitely. When a new overshoot or lag point appears later, the controller recalculates the repressurization deviation state and updates the adjustment strategy accordingly. If no overshoot or lag point has occurred in the current repressurization stage, resulting in no repressurization deviation state being calculated, the controller can use the airbag pressure change rate as an auxiliary control basis. Specifically, when the airbag pressure change rate is lower than the lower limit of the preset repressurization speed allowable range, it indicates that the current repressurization speed is insufficient, and the controller increases the output intensity of the inflation device; when the airbag pressure change rate is higher than the upper limit of the preset repressurization speed allowable range, it indicates that the current repressurization speed is too fast, and the controller reduces the output intensity of the inflation device; when the airbag pressure change rate is within the preset repressurization speed allowable range, the controller maintains the current output state of the inflation device.

[0024] When the current pressure deviation is within the pressure deviation balance range, the current output state of the inflation device is maintained, or the output state of the inflation device is finely adjusted according to the difference between the airbag pressure value and the lower limit of the high pressure reference.

[0025] The output intensity of an inflation device refers to the control quantity of its ability to output gas to the airbag within a unit control cycle. This includes at least one of the following: the output duty cycle of the inflation pump, its rotational speed, drive voltage, drive current, the number of inflation pulses per unit time, or the duration of continuous inflation. In this embodiment, increasing or decreasing the output intensity of the inflation device is not limited to a single hardware form. When the inflation device is an electric inflation pump, this can be achieved by adjusting the motor speed, drive voltage, drive current, or PWM duty cycle. When the inflation device uses pulse-type inflation control, this can be achieved by adjusting the number of inflation pulses per unit time or the duration of a single continuous inflation. All of these parameters change the amount of gas entering the airbag within a unit control cycle, and therefore can all be used as methods to achieve the output intensity of the inflation device.

[0026] Pressure relief correction refers to the process where, when the current pressure deviation exceeds the upper limit of the balance and the airbag pressure value reaches the lower limit of the high-pressure reference, the pressure relief device is activated according to a preset pressure relief pulse. After each pressure relief pulse ends, the airbag pressure value and airbag pressure change rate are reacquired. If the airbag pressure value is still higher than the lower limit of the high-pressure reference and the airbag pressure change rate is still greater than zero, the next pressure relief pulse is executed. If the airbag pressure change rate is less than or equal to zero, or the airbag pressure value falls back to near the lower limit of the high-pressure reference, pressure relief correction is stopped.

[0027] In this invention, the preset high-pressure holding range and preset low-pressure release range are both airbag pressure value ranges pre-stored by the controller or set by parameters before use, rather than state descriptions based solely on experience. Specifically, the preset high-pressure holding range includes a lower limit and an upper limit, and the preset low-pressure release range includes a lower limit and an upper limit, with the upper limit being smaller than the lower limit. These pressure limits can be set according to the product specifications of the automatic tourniquet, airbag volume, inflation device output capacity, pressure relief component response characteristics, and preset operating modes, and stored in the controller. During operation, the controller acquires the airbag pressure value in real time through a pressure sensor and compares it with the aforementioned pressure limits to determine whether the automatic tourniquet is in a high-pressure holding state, a low-pressure release state, or a repressurization transition state.

[0028] To avoid repeated switching of the airbag pressure near the range boundaries, this invention allows for setting confirmation times within preset high-pressure holding ranges and preset low-pressure release ranges. The airbag pressure value is not determined to be in a valid state simply by instantaneously entering the corresponding range; rather, it needs to be maintained within the corresponding pressure range for the preset confirmation time to confirm that the automatic tourniquet has entered either a high-pressure holding state or a low-pressure release state. Through these limitations, both the preset high-pressure holding range and the preset low-pressure release range have clear numerical boundaries and judgment conditions, enabling those skilled in the art to reproduce them based on specific product parameters.

[0029] Preferably, all undefined variables in this invention, if not explicitly defined, can be manually set thresholds.

[0030] This invention also provides an automatic tourniquet dynamic control system, comprising: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the automatic tourniquet dynamic control method. The automatic tourniquet dynamic control system can run on computing devices such as desktop computers, laptops, handheld computers, and cloud data centers. The runnable system may include, but is not limited to, processors, memory, and server clusters. The processor executes the computer program within the following system units: The tourniquet activation unit is used to activate the automatic tourniquet, control the airbag pressure to enter the preset high pressure holding range, and keep the automatic tourniquet in a high pressure holding state. The tourniquet pressure relief unit is used to control the airbag pressure to drop from the high pressure holding range to the preset low pressure release range when the pressure relief condition is reached, so that the automatic tourniquet is in the low pressure release state. The tourniquet repressure unit is used to control the airbag pressure to return from the low-pressure release range to the high-pressure holding range when the low-pressure release state ends, and to return to step S200 after the airbag pressure enters the high-pressure holding range. The tourniquet re-pressure unit includes: The pressure data acquisition unit is used to acquire the airbag pressure value and airbag pressure change rate in real time. The pressure deviation calculation unit is used to calculate the pressure deviation state based on the airbag pressure value and the airbag pressure change rate. The dynamic adjustment inflation unit is used to dynamically adjust the output state of the inflation device or the depressurization state of the depressurization component according to the pressure deviation state.

[0031] The beneficial effects of this invention are as follows: This invention provides an automatic tourniquet dynamic control method and system. It obtains the re-pressure deviation state through dynamic analysis of the balloon pressure value and the rate of change of the balloon pressure. This quantifies the risk of re-pressure lag or sudden overshoot caused by multiple cycles during the current re-pressure process, providing state variables for identifying the timing deviation and stability decrease of the high-pressure hemostasis platform in multiple inflation / deflation cycles. Especially when continuously obtaining low-volatility morphological data and insufficient updates to overshoot or lag points, the invention reduces the risk of control lag and sensitivity loss caused by missing source data through the re-pressure deviation balance sample set and pressure relief correction mechanism. This significantly improves the continuity of overshoot and lag identification, the timeliness of control response, and the stability of high-pressure maintenance state recovery during the re-pressure stage. Consequently, the tourniquet can more stably restore the high-pressure compression state after low-pressure release, reducing insufficient compression time caused by slow re-pressure, while suppressing pressure overshoot and protective pressure relief caused by excessively rapid re-pressure. This allows the tourniquet to maintain a more reliable hemostatic pressure platform during multiple decompression and re-pressure cycles, reducing the risk of continuous bleeding, rebleeding, and frequent pressure fluctuations. Attached Figure Description

[0032] The above and other features of the present invention will become more apparent from the detailed description of the embodiments shown in conjunction with the accompanying drawings. In the accompanying drawings, the same reference numerals denote the same or similar elements. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort. In the drawings: Figure 1 The diagram shows a flowchart of an automatic tourniquet dynamic control method. Figure 2 The diagram shown is a structural diagram of an automatic tourniquet dynamic control system. Detailed Implementation

[0033] The following will provide a clear and complete description of the concept, specific structure, and technical effects of the present invention in conjunction with the embodiments and accompanying drawings, so as to fully understand the purpose, solution, and effects of the present invention. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0034] like Figure 1 The diagram shown is a flowchart of an automatic tourniquet dynamic control method. The following section will discuss this method in conjunction with... Figure 1 This invention describes a dynamic control method for an automatic tourniquet according to an embodiment of the present invention, the method comprising the following steps: S100, activate the automatic tourniquet, control the airbag pressure to enter the preset high pressure holding range, so that the automatic tourniquet is in a high pressure holding state; S200, when the pressure relief condition is reached, the pressure of the airbag is controlled to drop from the high pressure holding range to the preset low pressure release range, so that the automatic tourniquet is in the low pressure release state. S300, when the low-pressure release state ends, control the airbag pressure to return from the low-pressure release range to the high-pressure holding range, and return to step S200 after the airbag pressure enters the high-pressure holding range. Step S300, in the process of restoring the airbag pressure from the low-pressure release range to the high-pressure holding range, includes: S301, real-time acquisition of airbag pressure value and airbag pressure change rate; S302, calculate the re-pressure deviation state based on the airbag pressure value and the airbag pressure change rate; S303, dynamically adjusts the output state of the inflation device or the pressure relief state of the pressure relief component according to the pressure deviation state.

[0035] Further, in step S100, the method for controlling the airbag pressure to enter the preset high-pressure holding range so that the automatic tourniquet is in a high-pressure holding state is as follows: the real-time pressure value of the airbag is obtained, and the inflation device is controlled to inflate the airbag according to the relationship between the real-time pressure value of the airbag and the preset high-pressure holding range; when the real-time pressure value of the airbag enters the preset high-pressure holding range, the real-time pressure value of the airbag is monitored, and if the real-time pressure value of the airbag is maintained within the preset high-pressure holding range within a preset confirmation time, it is determined that the automatic tourniquet is in a high-pressure holding state.

[0036] The controller acquires the real-time pressure value of the airbag and compares it with a preset high-pressure holding range. When the real-time pressure value is lower than the preset high-pressure holding range, the controller inflates the airbag, increasing its pressure. Once the real-time pressure value enters the preset high-pressure holding range, the controller does not immediately classify it as a high-pressure holding state, but continues to monitor the real-time pressure value for a preset confirmation time. If the real-time pressure value remains within the preset high-pressure holding range within the preset confirmation time, it indicates that the airbag pressure has transitioned from a pressurization transition state to a relatively stable state, confirming that the automatic tourniquet is in a high-pressure holding state.

[0037] Further, in step S200, when the pressure relief condition is met, the method for controlling the airbag pressure to decrease from the high pressure holding range to the preset low pressure release range, so that the automatic tourniquet is in a low pressure release state, is as follows: when the preset pressure relief condition is met, the pressure relief component is opened to reduce the airbag pressure; after the real-time pressure value of the airbag enters the preset low pressure release range, the pressure relief component is closed or the pressure relief intensity is reduced, and when the real-time pressure value of the airbag remains within the preset low pressure release range within the preset release confirmation time, the low pressure release state is determined.

[0038] The pressure relief conditions may include the high pressure holding time reaching a preset holding time, receiving a pressure relief control command, or meeting other preset cyclic control conditions.

[0039] The controller acquires the airbag pressure value in real time. When it determines that the preset pressure release condition is met, it controls the pressure relief device to open, allowing gas to escape from the airbag and causing the airbag pressure to decrease from the preset high-pressure range. During the airbag pressure decrease, the controller continuously monitors the real-time airbag pressure value. When the real-time airbag pressure value enters the preset low-pressure release range, it controls the pressure relief device to close or reduce the pressure relief intensity to prevent the airbag pressure from continuing to decrease below the preset low-pressure release range. After the real-time airbag pressure value enters the preset low-pressure release range, the controller continues to monitor the real-time airbag pressure value for a preset release confirmation time. If the real-time airbag pressure value remains within the preset low-pressure release range within the preset release confirmation time, the automatic tourniquet is determined to be in a low-pressure release state.

[0040] Further, in step S300, when the low-pressure release state ends, the method for controlling the airbag pressure to return from the low-pressure release range to the high-pressure holding range, and returning to step S200 after the airbag pressure enters the high-pressure holding range, is as follows: when the preset re-pressure condition is met, the inflation device is controlled to inflate the airbag, causing the airbag pressure to rise from the preset low-pressure release range; after the real-time airbag pressure value enters the preset high-pressure holding range, the output of the inflation device is stopped or reduced, and when the real-time airbag pressure value remains within the preset high-pressure holding range within the preset re-pressure confirmation time, it is determined that the automatic tourniquet is back in the high-pressure holding state, and the process returns to step S200.

[0041] Step S300 is used to restore the airbag pressure to a preset high-pressure holding range after the low-pressure release state ends, and to re-enter the high-pressure holding state of the automatic tourniquet. The preset re-pressure conditions may include the low-pressure release time reaching a preset release time, receiving a re-pressure control command, or meeting other preset cycle control conditions.

[0042] Specifically, the controller acquires the real-time airbag pressure value during or at the end of the low-pressure release process. When it determines that the preset re-pressure condition is met, it controls the inflation device to inflate the airbag, causing the airbag pressure to gradually rise from the preset low-pressure release range. During the airbag pressure rise, the controller continuously monitors the real-time airbag pressure value; when the real-time airbag pressure value enters the preset high-pressure holding range, it stops or reduces the output of the inflation device to prevent the airbag pressure from continuing to rise and significantly exceeding the preset high-pressure holding range.

[0043] Furthermore, after the real-time pressure value of the airbag enters the preset high-pressure holding range, the controller continues to monitor the real-time pressure value of the airbag within a preset re-pressure confirmation time. If the real-time pressure value of the airbag remains within the preset high-pressure holding range within the preset re-pressure confirmation time, it is determined that the automatic tourniquet has re-entered the high-pressure holding state from the low-pressure release state, and the process returns to step S200 to continue determining the next round of pressure release conditions.

[0044] Furthermore, in step S301, the method for acquiring the airbag pressure value and airbag pressure change rate in real time is as follows: when the low-pressure release state ends and the repressurization process begins, the airbag pressure value is continuously collected according to the preset sampling period. The preset sampling period is 20 times, and the time when the airbag pressure value data is obtained each time is recorded as the sampling time. The preset sampling period can be set according to the response speed of the pressure sensor, the computing power of the controller, and the pressurization speed of the inflation device. For example, it can be set to a fixed period in the range of several milliseconds to several hundred milliseconds, as long as it can meet the requirements of pressure change tracking during the repressurization process.

[0045] After obtaining the airbag pressure value at each sampling time, the airbag pressure change rate is calculated based on the ratio of the pressure difference between the airbag and the previous sampling time to the fixed period length.

[0046] The airbag pressure change rate is the difference between the airbag pressure value at the current sampling time and the airbag pressure value at the previous sampling time, divided by the time interval between adjacent sampling times, to obtain the real-time rise rate of airbag pressure during the repressurization process. When the airbag pressure change rate is large, it indicates that the current repressurization speed is fast, and the repressurization overshoot tendency should be monitored in subsequent control. When the airbag pressure change rate is small, it indicates that the current repressurization speed is slow, and the repressurization lag tendency should be monitored in subsequent control.

[0047] Further, in step S302, the method for calculating the re-pressure deviation state based on the airbag pressure value and the airbag pressure change rate is as follows: obtain the airbag pressure value in the high pressure maintenance state before the current depressurization to form a high pressure sequence, and define the lower quartile value of the high pressure sequence as the lower limit of the high pressure reference. The airbag pressure value measured at the end of the low-pressure release state is defined as the low-pressure reference pressure, and the difference between the lower limit of the high-pressure reference and the low-pressure reference pressure is the pressure application interval; then the difference between the airbag pressure value and the low-pressure reference pressure at any sampling time is recorded as the pressure application degree, and the ratio of the pressure application degree to the pressure application interval is recorded as the repressurization ratio. The difference between the re-voltage ratio at any sampling time and the previous sampling time is denoted as the re-voltage residual. If the rate of change of airbag pressure is less than the preset pressure increase threshold, it is determined that a pressure lag has occurred; otherwise, it is determined that a pressure overshoot has occurred. A time domain is preset as the hostage interval, with a value of 1 second; If the airbag pressure change rate at a sampling time is at a maximum value and pressure overshoot occurs, it is marked as an overshoot point. If the airbag pressure change rate at a sampling time is at a minimum value and pressure lag occurs, it is marked as a lag point. The proportion of sampling times in the holding interval where pressure overshoot occurs corresponding to the overshoot point is defined as the overshoot rate. The product of the maximum value of the re-pressure residual at the sampling time where pressure overshoot occurs and the overshoot rate is the overshoot fraction. The proportion of sampling times in the strangulation interval where pressure lag occurs corresponding to the lag point is defined as the lag rate. The product of the absolute value of the minimum value of the repressurization residual in the sampling time where pressure lag occurs and the lag rate is the lag fraction. During the re-pressure process, the re-pressure deviation is calculated each time a lag point or overshoot point is detected. The calculation method is the ratio of the weighted average of all overshoot fractions to the time-weighted average of all lag fractions. The corresponding weight of the time-weighted average is the time-weight value, which defaults to exp(-ti), where exp is an exponential function with the natural constant e as the base, and ti is the number of sampling times between the lag point or overshoot point and the current sampling time. The larger the value, the farther away it is from the current sampling time.

[0048] Preferably, the method of calculating the re-pressure deviation state every time a lag point or overshoot point is found is replaced by: calculating the re-pressure deviation state once at each sampling moment during the re-pressure process; Within the current holding interval, the proportion of sampling times where pressure boosting overshoot occurs is recorded as the current overshoot rate. The maximum value of the complex pressure residual within the current holding interval is extracted as the positive extreme value of the complex pressure residual. The current overshoot rate and the current positive extreme value of the complex pressure residual are combined into a pair, which is recorded as the overshoot pair. Here, the current holding interval refers to the holding interval corresponding to the current sampling time. The percentage of sampling times with pressurization lag within the current holding interval is used as the current lag rate. The remaining pressurization ratio is calculated from the pressurization ratio. The current lag rate and the remaining pressurization ratio are combined to form the lag tuple corresponding to the current sampling time. The remaining repressurization ratio here is the difference between 1 and the repressurization ratio; The overshoot pairs corresponding to the overshoot points marked in the current re-pressing process and the previous at least one re-pressing process are used to form an overshoot pair set, and the lag pairs corresponding to the lag points marked in the current re-pressing process and the previous at least one re-pressing process are used to form a lag pair set. The overshoot fitting operator is obtained based on the normalized distance between the current overshoot binary and the set of overshoot binary; the lag fitting operator is obtained based on the normalized distance between the current lag binary and the set of lag binary; the complex pressure deviation state is calculated based on the overshoot fitting operator and the lag fitting operator.

[0049] The calculation process of the overshoot fitting operator is as follows: First, normalize the two features in the overshoot binary pair respectively, and take the Euclidean distance between the current overshoot binary pair and any element in the overshoot binary pair set as the overshoot distance dj, and take the average value of each exp(-dj) as the overshoot fitting operator. The calculation process of the lag fitting operator is as follows: First, normalize the two features in the lag pair respectively, and take the Euclidean distance between the current lag pair and any element in the lag pair set as the lag sub-distance di, and take the average value of each exp(-di) as the lag fitting operator.

[0050] Specifically, the complex pressure deviation state R is calculated based on the overshoot fitting operator and the hysteresis fitting operator. k The process is as follows: the current sampling time is recorded as the k-th sampling time, and all sampling times within the current holding interval are used to form a sampling time set Ωk; for any sampling time i in Ωk, the interval between the number of sampling times between the i-th sampling time and the current sampling time is recorded as t. i , where t i =ki; denote the overshoot fitting operator corresponding to the i-th sampling time as O. i Let L be the hysteresis fitting operator corresponding to the i-th sampling time. i According to formula R k =[Σ i∈Ωk exp(-t i )·O i ] / [Σ i∈Ωk exp(-t i )·L i +ε], where exp() is an exponential function with the natural constant e as the base, ε is a minimal positive number to prevent the denominator from being zero, and R kA larger value indicates a greater tendency for overshoot in the current complex pressure state, while a smaller value indicates a greater tendency for lag. In the formula, the numerator represents the cumulative overshoot fitting degree of all sampling times within the current clamping interval after time-weighted adjustment, and the denominator is the cumulative lag fitting degree of all sampling times after time-weighted adjustment. The exponential function is used to interpret data timeliness and avoid the influence of early overshoot or lag on aging. Preferably, exp(-ti) is expressed as exp( t i / λ) is replaced by λ, which is the time-related attenuation coefficient used to adapt to different sampling frequencies.

[0051] Further, in step S303, the method for dynamically adjusting the output state of the inflation device or the depressurization state of the depressurization component according to the repressurization deviation state is as follows: the change rate of the airbag pressure calculated in the current repressurization stage and at least one previous repressurization stage is used to form a change rate set; the elements in the change rate set whose values ​​are within the preset repressurization speed range are recorded as the standard change rate, and the repressurization deviation state corresponding to each standard change rate constitutes a repressurization deviation balance sample set. The deviation range of complex pressure from equilibrium is determined based on the complex pressure deviation from equilibrium sample set, wherein the lower quartile value of the complex pressure deviation from equilibrium sample set is used as the lower limit of equilibrium, and the upper quartile value of the complex pressure deviation from equilibrium sample set is used as the upper limit of equilibrium. When the current repressurization deviation is below the lower limit of the repressurization deviation equilibrium range, it is determined that the current repressurization process is mainly characterized by repressurization lag, and the output intensity of the inflation device is increased by 5%. When the current repressurization deviation is higher than the upper limit of the repressurization deviation balance range, it is determined that the current repressurization process is mainly due to repressurization overshoot, and the output intensity of the inflation device is reduced by 5%; or the pressure relief component is controlled to perform pressure relief correction after the airbag pressure value reaches the lower limit of the high pressure reference.

[0052] To ensure the continuity of control in step S303, when no new repressurization deviation state is generated at the current sampling time, the controller can use the most recently calculated repressurization deviation state to adjust the output of the inflation device. Since the repressurization deviation state is constructed using time-dependent weights, the influence of historical points further from the current time is weaker; therefore, using the most recently calculated repressurization deviation state will not dominate subsequent control indefinitely. When a new overshoot or lag point appears later, the controller recalculates the repressurization deviation state and updates the adjustment strategy accordingly. If no overshoot or lag point has occurred in the current repressurization stage, resulting in no repressurization deviation state being calculated, the controller can use the airbag pressure change rate as an auxiliary control basis. Specifically, when the airbag pressure change rate is lower than the lower limit of the preset repressurization speed allowable range, it indicates that the current repressurization speed is insufficient, and the controller increases the output intensity of the inflation device; when the airbag pressure change rate is higher than the upper limit of the preset repressurization speed allowable range, it indicates that the current repressurization speed is too fast, and the controller reduces the output intensity of the inflation device; when the airbag pressure change rate is within the preset repressurization speed allowable range, the controller maintains the current output state of the inflation device.

[0053] When the current pressure deviation is within the pressure deviation balance range, the current output state of the inflation device is maintained, or the output state of the inflation device is finely adjusted according to the difference between the airbag pressure value and the lower limit of the high pressure reference.

[0054] The output intensity of an inflation device refers to the control quantity of its ability to output gas to the airbag within a unit control cycle. This includes at least one of the following: the output duty cycle of the inflation pump, its rotational speed, drive voltage, drive current, the number of inflation pulses per unit time, or the duration of continuous inflation. In this embodiment, increasing or decreasing the output intensity of the inflation device is not limited to a single hardware form. When the inflation device is an electric inflation pump, this can be achieved by adjusting the motor speed, drive voltage, drive current, or PWM duty cycle. When the inflation device uses pulse-type inflation control, this can be achieved by adjusting the number of inflation pulses per unit time or the duration of a single continuous inflation. All of these parameters change the amount of gas entering the airbag within a unit control cycle, and therefore can all be used as methods to achieve the output intensity of the inflation device.

[0055] An embodiment of the present invention provides an automatic tourniquet dynamic control system, such as... Figure 2 The diagram shown is a structural diagram of an automatic tourniquet dynamic control system according to the present invention. The automatic tourniquet dynamic control system of this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps in the above-described embodiment of the automatic tourniquet dynamic control method.

[0056] The system includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program in units of the following system: The tourniquet activation unit is used to activate the automatic tourniquet, control the airbag pressure to enter the preset high pressure holding range, and keep the automatic tourniquet in a high pressure holding state. The tourniquet pressure relief unit is used to control the airbag pressure to drop from the high pressure holding range to the preset low pressure release range when the pressure relief condition is reached, so that the automatic tourniquet is in the low pressure release state. The tourniquet repressure unit is used to control the airbag pressure to return from the low-pressure release range to the high-pressure holding range when the low-pressure release state ends, and to return to step S200 after the airbag pressure enters the high-pressure holding range. The tourniquet re-pressure unit includes: The pressure data acquisition unit is used to acquire the airbag pressure value and airbag pressure change rate in real time. The pressure deviation calculation unit is used to calculate the pressure deviation state based on the airbag pressure value and the airbag pressure change rate. The dynamic adjustment inflation unit is used to dynamically adjust the output state of the inflation device or the depressurization state of the depressurization component according to the pressure deviation state.

[0057] The aforementioned automatic tourniquet dynamic control system can run on computing devices such as desktop computers, laptops, handheld computers, and cloud servers. The system that can run on the aforementioned automatic tourniquet dynamic control system may include, but is not limited to, processors and memory. Those skilled in the art will understand that the examples described are merely illustrations of an automatic tourniquet dynamic control system and do not constitute a limitation on such a system. It may include more or fewer components, combinations of certain components, or different components. For example, the aforementioned automatic tourniquet dynamic control system may also include input / output devices, network access devices, buses, etc.

[0058] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the automatic tourniquet dynamic control system, connecting all parts of the system via various interfaces and lines.

[0059] The memory can be used to store the computer programs and / or modules. The processor implements various functions of the automatic tourniquet dynamic control system by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory. The memory may mainly include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback function, image playback function, etc.), etc.; the data storage area may store data created according to the use of the mobile phone (such as audio data, phonebook, etc.). In addition, the memory may include high-speed random access memory, and may also include non-volatile memory, such as hard disk, memory, plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0060] Although the invention has been described in considerable detail and particularly with regard to several of the described embodiments, it is not intended to limit itself to any of these details or embodiments or any particular embodiment, thereby effectively covering the intended scope of the invention. Furthermore, the invention has been described above with respect to embodiments foreseeable by the inventors in order to provide a useful description, and non-substantial modifications to the invention that have not yet been foreseen may still represent equivalent modifications.

Claims

1. A method for dynamic control of an automatic tourniquet, characterized in that, The method includes the following steps: S100, activate the automatic tourniquet, control the airbag pressure to enter the preset high pressure holding range, so that the automatic tourniquet is in a high pressure holding state; S200, when the pressure relief condition is reached, the pressure of the airbag is controlled to drop from the high pressure holding range to the preset low pressure release range, so that the automatic tourniquet is in the low pressure release state. S300, when the low-pressure release state ends, control the airbag pressure to return from the low-pressure release range to the high-pressure holding range, and return to step S200 after the airbag pressure enters the high-pressure holding range. Step S300, in the process of restoring the airbag pressure from the low-pressure release range to the high-pressure holding range, includes: S301, real-time acquisition of airbag pressure value and airbag pressure change rate; S302, calculate the re-pressure deviation state based on the airbag pressure value and the airbag pressure change rate; S303, dynamically adjusts the output state of the inflation device or the pressure relief state of the pressure relief component according to the pressure deviation state.

2. The automatic tourniquet dynamic control method according to claim 1, characterized in that, In step S100, the method for controlling the airbag pressure to enter the preset high-pressure holding range and keeping the automatic tourniquet in a high-pressure holding state is as follows: obtain the real-time pressure value of the airbag, and control the inflation device to inflate the airbag according to the relationship between the real-time pressure value of the airbag and the preset high-pressure holding range; after the real-time pressure value of the airbag enters the preset high-pressure holding range, continue to monitor the real-time pressure value of the airbag, and if the real-time pressure value of the airbag is kept within the preset high-pressure holding range within a preset confirmation time, it is determined that the automatic tourniquet is in a high-pressure holding state.

3. The automatic tourniquet dynamic control method according to claim 1, characterized in that, In step S200, when the pressure relief condition is met, the method to control the airbag pressure to drop from the high pressure holding range to the preset low pressure release range so that the automatic tourniquet is in the low pressure release state is: when the preset pressure relief condition is met, the pressure relief component is controlled to open so that the airbag pressure drops. After the real-time pressure value of the airbag enters the preset low-pressure release range, the pressure relief component is controlled to close or the pressure relief intensity is reduced, and the low-pressure release state is determined when the real-time pressure value of the airbag remains within the preset low-pressure release range within the preset release confirmation time.

4. The automatic tourniquet dynamic control method according to claim 1, characterized in that, In step S300, when the low-pressure release state ends, the method for controlling the airbag pressure to return from the low-pressure release range to the high-pressure holding range, and returning to step S200 after the airbag pressure enters the high-pressure holding range, is as follows: when the preset re-pressure condition is met, the inflation device is controlled to inflate the airbag, causing the airbag pressure to rise from the preset low-pressure release range; after the real-time airbag pressure value enters the preset high-pressure holding range, the output of the inflation device is stopped or reduced, and when the real-time airbag pressure value remains within the preset high-pressure holding range within the preset re-pressure confirmation time, it is determined that the automatic tourniquet is back in the high-pressure holding state, and the process returns to step S200.

5. The automatic tourniquet dynamic control method according to claim 1, characterized in that, In step S301, the method for obtaining the airbag pressure value and airbag pressure change rate in real time is as follows: when the low-pressure release state ends and the repressurization process begins, the airbag pressure value is continuously collected according to the preset sampling period. After obtaining the airbag pressure value at each sampling time, the airbag pressure change rate is calculated based on the ratio of the pressure difference between the airbag and the previous sampling time to the fixed period length.

6. The automatic tourniquet dynamic control method according to claim 1, characterized in that, In step S302, the method for calculating the re-pressure deviation state based on the airbag pressure value and the airbag pressure change rate is as follows: obtain the airbag pressure value in the high pressure maintenance state before the current depressurization to form a high pressure sequence, and define the lower quartile value of the high pressure sequence as the lower limit of the high pressure reference. The airbag pressure value measured at the end of the low-pressure release state is defined as the low-pressure reference pressure, and the difference between the lower limit of the high-pressure reference and the low-pressure reference pressure is the pressure application interval; then the difference between the airbag pressure value and the low-pressure reference pressure at any sampling time is recorded as the pressure application degree, and the ratio of the pressure application degree to the pressure application interval is recorded as the repressurization ratio. The difference between the complex pressure ratio at any sampling time and the previous sampling time is denoted as the complex pressure residual. If the rate of change of airbag pressure is less than the preset inflation threshold, it is determined that an inflation lag has occurred; otherwise, it is determined that an inflation overshoot has occurred. A time domain is predefined as the holding interval. If the airbag pressure change rate at a sampling moment reaches a maximum and pressure overshoot occurs, it is marked as an overshoot point. If the airbag pressure change rate at a sampling moment reaches a minimum and pressure lag occurs, it is marked as a lag point. The proportion of sampling moments in the holding interval where pressure overshoot occurs corresponding to the overshoot point is defined as the overshoot rate, where the product of the maximum value of the recompression residual at the sampling moment where pressure overshoot occurs and the overshoot rate is the overshoot fraction. The proportion of sampling moments in the holding interval where pressure lag occurs corresponding to the lag point is defined as the lag rate, where the product of the absolute value of the minimum value of the recompression residual at the sampling moment where pressure lag occurs and the lag rate is the lag fraction. Whenever a lag point or overshoot point is detected, the pressure deviation state is calculated once. The calculation method is the ratio of the weighted average of all overshoot fractions to the time-weighted average of all lag fractions.

7. The automatic tourniquet dynamic control method according to claim 6, characterized in that, The method of calculating the re-pressure deviation state every time a lag point or overshoot point is found is replaced by: calculating the re-pressure deviation state once at each sampling moment during the re-pressure process; Within the current holding interval, the proportion of sampling times where pressure overshoot occurs is recorded as the current overshoot rate. The maximum value of the complex pressure residual within the current holding interval is extracted as the positive extreme value of the complex pressure residual. The current overshoot rate and the current positive extreme value of the complex pressure residual are combined into a pair, which is recorded as the overshoot pair. The percentage of sampling times with pressurization lag within the current holding interval is used as the current lag rate. The remaining pressurization ratio is calculated from the pressurization ratio. The current lag rate and the remaining pressurization ratio are combined to form the lag tuple corresponding to the current sampling time. The overshoot pairs corresponding to the overshoot points marked in the current re-pressing process and the previous at least one re-pressing process are used to form an overshoot pair set, and the lag pairs corresponding to the lag points marked in the current re-pressing process and the previous at least one re-pressing process are used to form a lag pair set. The overshoot fitting operator is obtained based on the normalized distance between the current overshoot binary and the set of overshoot binary; the lag fitting operator is obtained based on the normalized distance between the current lag binary and the set of lag binary; the complex pressure deviation state is calculated based on the overshoot fitting operator and the lag fitting operator.

8. The automatic tourniquet dynamic control method according to claim 1, characterized in that, In step S303, the method for dynamically adjusting the output state of the inflation device or the depressurization state of the depressurization component according to the repressurization deviation state is as follows: the change rate of the airbag pressure calculated in the current repressurization stage and at least one previous repressurization stage is used to form a change rate set; the elements in the change rate set whose values ​​are within the preset repressurization speed range are recorded as the standard change rate, and the repressurization deviation state corresponding to each standard change rate forms a repressurization deviation balance sample set. The deviation interval of complex pressure from equilibrium is determined based on the set of samples showing deviation from equilibrium of complex pressure. When the pressure deviation is below the lower limit of the pressure deviation balance range, the output intensity of the inflation device is increased; when the pressure deviation is above the upper limit of the pressure deviation balance range, the output intensity of the inflation device is decreased; or the pressure relief component is controlled to perform pressure relief correction after the airbag pressure value reaches the lower limit of the high pressure reference.

9. An automatic tourniquet dynamic control system, characterized in that, The automatic tourniquet dynamic control system includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the automatic tourniquet dynamic control method according to any one of claims 1-8. The automatic tourniquet dynamic control system operates on a desktop computer, a laptop computer, a handheld computer, or a cloud data center computing device.

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